(a) Field of the Invention
The present invention relates to an intelligent cruise control system, and more particularly, to a method and system for acquiring vehicle driving-information in an intelligent cruise control system.
(b) Description of the Related Art
Recently, a vehicle equipped with an intelligent cruise control system (referred to as xe2x80x9cICC vehiclexe2x80x9d hereinafter) has been under development, where the intelligent cruise control system (referred to as xe2x80x9cICC systemxe2x80x9d hereinafter) is a system for automatically controlling a vehicle speed, including braking and accelerating of the vehicle, when the ICC system is activated.
One of a radar sensor or a laser sensor is used in such an ICC system for measuring a distance to a preceding vehicle, of which the radar sensor is more widely used because the laser sensor is substantially affected by circumstantial factors such as rain and fog.
Also, such an ICC system includes a steering angle sensor (or yaw-rate sensor) for detecting a steering angle (or a yaw-rate) that is used as a parameter while following a preceding vehicle during driving on a curved road.
Therefore, it must be determined whether the preceding vehicle is running in the same lane with an ICC vehicle, which is realized, for a general ICC system using a radar sensor, by detecting an apart-angle (that is, an angle between the direction that the ICC vehicle is aiming and the direction toward the preceding vehicle) and comparing the detected apart-angle with a predetermined angle.
Such a simple method for determining whether a preceding vehicle is running in the same lane is found to be reliable in cases in which both the preceding vehicle and the ICC vehicle are running on a straight portion of the road or both are in a curved region. However, in a case that only one of the preceding vehicle and the ICC vehicle is running on a straight portion and the other is running in a curved region, that is, in a case in which a preceding vehicle has just entered the curved region and a following ICC vehicle has not yet entered the curved region, or in a case in which a preceding vehicle has just left a curved region while the following ICC vehicle is still in the curved region, the result of the prior method is not satisfactory.
The present invention is a method and a system for acquiring vehicle driving information that increases reliability when only one of a preceding vehicle and an ICC vehicle is in a curved region of a road.
The present invention provides a method for acquiring driving information of a following vehicle comprising detecting a distance to a preceding vehicle; detecting an apart-angle of the preceding vehicle; detecting an amplitude of a reflective wave reflected by the preceding vehicle; and determining, on the basis of the detected apart-angle and the detected amplitude of a reflective wave, whether the preceding vehicle is in the same lane as the following vehicle.
In the determining whether the preceding vehicle is in the same lane, it is determined that the preceding vehicle is running in the same lane if the detected apart-angle is greater than a predetermined angle and the detected amplitude of the reflective wave is less than a predetermined reference amplitude, where the predetermined reference amplitude preferably depends on the distance to the preceding vehicle and the apart-angle of the preceding vehicle.
In the determining whether the preceding vehicle is in the same lane, it is determined that the preceding vehicle is not running in the same lane if the detected apart-angle is not greater than a predetermined angle and the detected amplitude of the reflective wave is less than a predetermined reference amplitude, where the predetermined reference amplitude depends on the distance to the preceding vehicle and the apart-angle of the preceding vehicle.
If the preceding vehicle is running in the same lane or not, it can be further determined whether the following vehicle is running in the curved region, and based on the determination, it is determined that the following vehicle is exiting from the curved region if it is determined the following vehicle is running in the curved region; and it is determined that the following vehicle is entering into the curved region if it is determined that the following vehicle is not running in the curved region. It is on the basis of a steering angle or yaw rate of the following vehicle that it is determined whether the following vehicle is running in the curved region.
The method of the present invention is realized by a system for acquiring driving information of a following vehicle comprising a detecting unit for detecting a distance from the following vehicle to a preceding vehicle, and an amplitude of a reflective wave reflected from the preceding vehicle; a steering angle detector for detecting a steering angle of the following vehicle; and a control unit for acquiring the driving information based on detected values detected by the detecting unit, wherein the control unit performs each of the steps of the method of the present invention.